Today's tech companies are generally real businesses with real profits. The market for public stocks is not overheated. In fact it's actually pretty cheap right now using traditional valuation metrics.

However, that doesn't mean we don't understand why other people think there's a bubble. Valuations have soared, money for startups has become easy to obtain, and the IPO market is looking a lot less chilly.

Sounds like it's time to party like it's 1999, right? Hardly. Read on to see why not.